Mitigation of hazardous toluene via ozone-catalyzed oxidation using MnOx/Sawdust biochar catalyst

Abstract

This study investigated catalytic ozone oxidation using a sawdust char (SDW) catalyst to remove hazardous toluene emitted from the chemical industry. The catalyst properties were analyzed by proximate, ultimate, nitrogen adsorption-desorption isotherms, Fourier-transform infrared, and X-ray photoelectron spectroscopy analyses. In addition, hydrogen-temperature programmed reduction experiments were conducted to analyze the catalyst properties. The specific area and formation of micropores of SDC were improved by applying KOH treatment. MnOx/SDC-K3 exhibited a higher toluene removal efficiency of 89.7% after 100 min than MnOx supported on activated carbon (MnOx/AC) with a removal efficiency of 6.6%. The higher (Oads (adsorbed oxygen)+Ov(vacancy oxygen))/OL (lattice oxygen) and Mn3+/Mn4+ ratios of MnOx/SDC-K3 than those of MnOx/AC seemed to be important for the catalytic oxidation of toluene.